Revenue bonds issued under the provisions of this chapter shall not be deemed to constitute a debt of such county or a pledge of the faith and credit of such county, but such bonds shall be payable solely from the special fund provided therefor as hereinafter set forth, and the issuance of such revenue bonds shall not directly, indirectly, or contingently obligate the county to levy or pledge any form of taxation whatever therefor, and all such bonds shall contain recitals on their face substantially covering the foregoing provisions of this section.